A conventional ratchet tool includes a ratchet mechanism which generally has a pawl member with teeth on two ends thereof and a toothed ring which is engaged with the pawl member. The pawl member has a lever connected thereto so that the user may shift the lever to let either end of the two toothed ends of the pawl member engage with the toothed ring so that the ratchet tool can output torque in a desired direction. The depth of the teeth of the ring and the pawl member is limited because deep depth of the teeth will make the pawl member and the ring to become too large to be a hand-operation tool. Furthermore, the lever connected to the pawl member is so small so that it is difficult to shift it especially the user's hand generally is adhered with lubricant or oil. Besides, the two ends of the pawl member has only limited teeth which cannot bear a large torque to be output when engaged with the toothed ring.
The present invention intends to provide a ratchet tool which has a cylindrical member received in a sleeve, the sleeve has three rollers retained therein and the cylindrical member has three plain surfaces so that when the rollers contact the surfaces, the tool can be rotated in one way, and when the periphery of the cylindrical member contacts the rollers, the sleeve and the cylindrical member are combined to be as a one-piece member.